CVE-2026-22094

Executive Summary

CVE-2026-22094 affects the firmware of the EVbee DC-80 device, which ships with a weak hardcoded root password. Because the SSH daemon on the device is exposed to the network, an unauthenticated remote attacker who knows or guesses the hardcoded credential can log in directly as root. Successful exploitation grants full administrative control of the device, enabling configuration tampering, data exfiltration, persistence, and use of the device as a pivot point into the surrounding network. No patch, public proof-of-concept, or EPSS score is currently available.

Technical Analysis

The vulnerability is classified as CWE-1391 (Use of Weak Credentials). The NVD description states that the firmware for the EVbee DC-80 contains a weak hardcoded root password and that the SSH daemon is exposed to the network. Two properties combine to produce the exposure:

1. Hardcoded credential. The root account password is fixed in firmware rather than generated per device or set by the operator at commissioning. This means the credential is identical across all units sharing the same firmware build and cannot be changed without a firmware update (or is resistant to change). Because it is "weak," it is also likely short, low-entropy, or based on a predictable pattern (e.g., a vendor default or product name). No specific password value, hash, or storage location is disclosed in the available description, so the exact string and its on-device storage format are not derivable from the data provided.

2. Exposed SSH daemon. The SSH service listens on the network, making the root account remotely reachable. Where the SSH daemon binds (management VLAN, LAN, or WAN-facing interface) is not specified in the NVD description. If the daemon is reachable from untrusted networks, the attack surface is correspondingly larger. The presence of SSH implies an interactive, privileged remote administration path with no described pre-authentication gate.

The attack surface is therefore the network-reachable SSH service on the DC-80. No authentication bypass logic, vulnerable function, or code defect beyond the credential weakness itself is described; the root cause is credential management, not a memory-safety or injection flaw. The authentication mechanism (password-based root login) is the vector, and the weakness is that the valid credential is both static and guessable.

This class of issue is common in embedded/IoT devices where firmware images are distributed to many units and credentials are compiled in or provisioned via a static default. Because SSH is an interactive protocol, a successful credential guess yields a fully interactive root shell rather than a single-shot command execution primitive.

Exploitation Scenarios

The following chain is described strictly from the NVD description; no public proof-of-concept is available, and the attack chain is inferred from the vulnerability class.

1. Reconnaissance / target identification. An attacker scans for hosts exposing SSH (TCP/22) and fingerprints EVbee DC-80 devices via service banners, management interfaces, or certificate/hostname artifacts. Internet- or network-wide scanning is sufficient to enumerate candidate targets, since the daemon is exposed to the network.

2. Credential acquisition. The attacker obtains the hardcoded credential. Because it is static and weak, this can occur through firmware extraction from an acquired image, vendor documentation, prior disclosures, or straightforward credential guessing/brute force against the root account. The description does not disclose the password value or its storage, so the precise acquisition method cannot be stated with certainty.

3. Authentication. The attacker connects to the exposed SSH daemon and authenticates as the root user with the hardcoded password. No exploit code, memory corruption, or authentication bypass is required — the flaw is that valid root credentials are predictable and immutable. This maps to T1078.001 (Valid Accounts: Default Accounts): the use of legitimate, default credentials rather than a software defect.

4. Post-exploitation impact. Root access provides full control of the device: reading and modifying configuration, accessing any data processed or stored by the DC-80, installing persistent access, and using the device as a foothold to reach other systems on its network segment. Because the session is authenticated and legitimate-looking, it may evade naive detection.

No public exploit, Nuclei template, or exploit code is available for this CVE as of this report. The attack is low-complexity and requires no user interaction, which is consistent with remote, unauthenticated reach leading to high confidentiality, integrity, and availability impact.

Impact Assessment

Successful exploitation yields complete compromise of the affected DC-80 device. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H reflects: network attack vector, low attack complexity, no privileges required, no user interaction, unchanged scope, and high impact to confidentiality, integrity, and availability. Note: no CVSS score has been assigned by the source data (score: N/A); the vector above is derived from the described characteristics and should be treated as an analytical assessment, not a vendor-published score.

Business impact. The DC-80 is a device whose firmware exposure grants root-level control. Consequences include:

• Unauthorized reconfiguration or disabling of device function (availability impact).
• Theft or tampering of data processed or stored by the device (confidentiality and integrity impact).
• Establishment of persistent root-level access invisible to ordinary users.
• Lateral movement: a rooted device on the network can be used to probe and reach adjacent systems, expanding the blast radius beyond the single device.

Blast radius. Any EVbee DC-80 reachable over the network — especially those with SSH exposed to untrusted or flat networks — is in scope. Because the credential is hardcoded, the risk is systemic across all units running the affected firmware rather than isolated to a single misconfigured host. No EPSS score is available, so exploitation likelihood cannot be quantitatively estimated from FIRST.org data at this time.

Detection Guidance

Sigma Rule

title: EVbee DC-80 Hardcoded Root SSH Login (CVE-2026-22094)
id: 8f3a1c2e-22094-4b7d-9e2a-evbeee000001
status: experimental
description: Detects successful SSH authentication as root to an EVbee DC-80 device, consistent with abuse of a hardcoded root credential.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-22094
author: valtersit.com
date: 2026/01/01
tags:
  - attack.initial_access
  - attack.t1078.001
logsource:
  product: linux
  service: sshd
detection:
  selection:
    program: sshd
    message|contains|all:
      - 'Accepted password for root'
      - 'ssh2'
  condition: selection
falsepositives:
  - Authorized administrative root logins over SSH
level: high

YARA Rule

rule CVE_2026_22094_EVbee_DC80_Hardcoded_Root
{
    meta:
        description = "Detects hardcoded credential indicators in EVbee DC-80 firmware images related to CVE-2026-22094"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-22094"
        date = "2026-01-01"
        hash = "unknown"
    strings:
        $prod  = "DC-80" ascii wide nocase
        $vend  = "EVbee" ascii wide nocase
        $ssh   = "sshd" ascii wide nocase
        $root  = "root" ascii
        $pass1 = "password" ascii nocase
        $pass2 = "passwd" ascii nocase
        $shadow = "/etc/shadow" ascii
    condition:
        (uint32(0) == 0x27051956) and  // U-Boot/uImage style magic (firmware container)
        $prod and $vend and ($ssh or $shadow) and ($root or $pass1 or $pass2)
}

Note: The YARA rule targets firmware-image artifacts and known product markers. It cannot match an unknown password value, because the credential is not disclosed in the source data.

Suricata IDS Rule

alert tcp any any -> any 22 (msg:"CVE-2026-22094 Possible EVbee DC-80 Root Login Attempt - repeated SSH auth"; flow:to_server,established; content:"SSH-"; depth:4; threshold: type both, track by_src, count 5, seconds 60; classtype:attempted-admin; sid:202622094; rev:1;)

Because the exploit uses legitimate SSH and a valid (hardcoded) credential, network detection is limited to behavioral signals: repeated authentication attempts against root on port 22 (brute force of the weak password) or anomalous source addresses successfully completing SSH sessions to DC-80 devices. The rule above flags high-rate authentication activity; it does not detect the specific password.

Elastic Detection

sequence by source.ip with maxspan=1m
  [authentication where event.outcome == "failure" and user.name == "root" and network.transport == "tcp" and destination.port == 22]
  [authentication where event.outcome == "success" and user.name == "root" and destination.port == 22]

Splunk SPL Query

index=* sourcetype=linux_secure "sshd"
| search ("Accepted password for root" OR "Failed password for root")
| rex field=_raw "from (?<src_ip>\d+\.\d+\.\d+\.\d+)"
| stats count(eval(searchmatch("Accepted password for root"))) as successes count(eval(searchmatch("Failed password for root"))) as failures by src_ip, host
| where successes > 0
| table host src_ip failures successes

Wazuh OSSEC Rule

<group name="syslog,sshd,cve-2026-22094,">
  <rule id="100094" level="12">
    <if_sid>5715</if_sid>
    <match>Accepted password for root</match>
    <description>CVE-2026-22094: Successful root SSH login - possible EVbee DC-80 hardcoded credential abuse</description>
    <mitre>
      <id>T1078.001</id>
    </mitre>
  </rule>
  <rule id="100095" level="10" frequency="5" timeframe="60">
    <if_sid>5710</if_sid>
    <match>Failed password for root</match>
    <description>CVE-2026-22094: Repeated failed root SSH logins - possible brute force of hardcoded credential</description>
    <mitre>
      <id>T1110</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor fix, firmware version, or advisory is currently available. The following measures reduce exposure in the absence of a patch.

1) Immediate mitigations

• Restrict network access to SSH (TCP/22) on all DC-80 devices using firewall rules or ACLs. Permit only trusted management hosts; block access from the internet and untrusted VLANs.
• Place DC-80 devices on an isolated management segment/VLAN so that a compromised unit cannot reach production systems.
• If the SSH daemon can be disabled or an alternate authentication method configured, disable password-based root login where operational requirements permit.
• Change the root password via any supported mechanism if the firmware allows it; where the credential is immutable, treat the device as untrusted.
• Monitor authentication logs for successful and failed root logins and alert on anomalies.

2) Patch / upgrade

• No patch is available. Monitor the EVbee vendor channel and the NVD entry for CVE-2026-22094 for a firmware update. When a fixed firmware version is released, stage and validate it before fleet-wide deployment. Do not assume any version is fixed until the vendor confirms it.

3) Long-term hardening

• Enforce a policy against statically provisioned or hardcoded credentials on embedded/IoT assets. Require unique per-device credentials or certificate-based authentication.
• Inventory all EVbee DC-80 units and any other devices sharing the affected firmware, and track them in an asset management system with firmware version tracking.
• Require SSH exposure only where justified, and standardize on key-based authentication for administrative access.
• Incorporate embedded-device credential review into procurement and vulnerability management programs; treat CWE-1391 as a recurring supply-chain risk for IoT.

References

• NVD — CVE-2026-22094: https://nvd.nist.gov/vuln/detail/CVE-2026-22094
• MITRE CWE-1391 — Use of Weak Credentials: https://cwe.mitre.org/data/definitions/1391.html
• MITRE ATT&CK T1078.001 — Valid Accounts: Default Accounts: https://attack.mitre.org/techniques/T1078/001/
• MITRE ATT&CK T1110 — Brute Force: https://attack.mitre.org/techniques/T1110/
• CISA Known Exploited Vulnerabilities Catalog (checked; CVE-2026-22094 not listed): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• FIRST EPSS (not yet scored for this CVE): https://api.first.org/data/v1/epss?cve=CVE-2026-22094

No threat actor campaigns, exploit-in-the-wild evidence, public proof-of-concept, or Nuclei template have been identified for this CVE at the time of writing. No vendor advisory or patch reference is available.